1. Field of the Invention
The invention relates to catalytic reduction of oxides of nitrogen, NO.sub.x, produced in the regenerators associated with catalytic cracking unit regenerators.
2. Description of Related Art
The presence of NO.sub.x, or oxides of nitrogen, in flue gas streams, is a pervasive problem. Several powerful ways have been developed to deal with the problem. The approaches fall into roughly three categories, process approaches which inherently reduce the amount of NO.sub.x formed in a regenerator, catalytic approaches using a catalyst or additive which is compatible with the FCC reactor, and stack gas cleanup methods which are isolated from the FCC process. The FCC process will be briefly reviewed, followed by a review of the state of the art in reducing NO.sub.x emissions.